1. Field of the Invention
The present invention generally relates to a method for manufacturing a magnetic head suspension assembly used for a magnetic disk unit or the like. More particularly, the present invention relates to a method of manufacturing a magnetic head suspension wherein a wiring member for connecting a magnetic head element with a read/write amplifier circuit board is integrally formed with a suspension.
2. Description of the Related Art
This type of magnetic disk unit is equipped with at least one rotary disk for magnetically recording information, a magnetic head element, for reading from or writing to, each track on the disk, and a head positioning actuator which is connected with the head element. The positioning actuator is used to move the head element to a desired track and maintain the head element above the selected track.
An example of a conventional magnetic head suspension assembly is disclosed in Japanese Patent Laid-Open No. 63-113917. In this art, the magnetic head element is attached to a flexure by epoxy resin or the like and the flexure is installed on a load beam by laser welding or the like. Gold-plated copper lead wire provided with urethane coating or the like is connected by ultrasonic bonding, soldering, or the like to an electrode formed on the magnetic head element, thus forming a leader wiring section for sending a signal from the magnetic head to an external circuit. The wiring member is turned a number of times before it is housed in a flexible insulating resinous tube and mounted on the suspension by crimping a part of the suspension or other similar means.
Such a magnetic head suspension assembly suffers from the problem that the connection between an electrode on the magnetic head element and the leader wiring is extremely inefficient due to restrictions on operability, making it difficult to achieve higher productivity. This problem has been exacerbated due to the increasing number of terminals resulting from the reduced sizes of magnetic head elements and the increasing use of MR elements in recent years. Furthermore, an additional problem arises because the rigidity of the leader wiring member prevents the magnetic head element from obtaining an optimum position when it floats. A final problem is that the leader wiring member is subjected to wind pressure from air flow produced by a rotating recording medium, which disturbs the position of a floating magnetic head element.
To solve these problems, the art disclosed under Japanese Patent Laid-Open No. 53-74414 employs a flexible circuit board, which also serves as the leader wiring member and the suspension mechanism to support the magnetic head element. This art, however, presents many problems in achieving accurate positioning, applying the appropriate load, and appropriate floating position of the magnetic head since these are all basically required of the suspension mechanism, it can hardly be employed for the magnetic disk units with higher density used these days.
According to one popular approach to solving the problems regarding conventional leader wiring, a flexible circuit board, which is used to include all wiring is attached to a suspension spring with an adhesive agent or the like. This approach, however, unavoidably trades off weight reduction for operability because a separate flexible circuit board must be glued to the suspension spring. Whereas, preferably, the composing member which serves as a servo mechanical element should be lighter to meet the demand for faster seek, etc.
Hence, there has been a demand for a magnetic head suspension assembly which reduces the adverse influences on the floating position of the magnetic head exerted by the leader wiring member and also permits easier mounting of the magnetic head element by combining the leader wiring member and the suspension into one piece.